Bacterial copper ore processing. Water flowing into a bioleaching bath, where copper is extracted from concentrated solutions of copper sulphide ores. Bioleaching uses natural micro-organisms to catalyse the oxidation of sulphide minerals, causing the deposition of copper precipitates (blue). This site is at the open-pit Skouriotissa copper mine, located near Lefka in north-west Cyprus. Mining of copper has taken place here for over 4000 years, with modern techniques including bioleaching and electrolysis.